THE SYSTEM OF HANDLING AIRCRAFT FUELS AND/OR MISSILE PROPELLANTS CAN BE SUBJECT TO FAILURE (MAJOR OR MINOR). SUCH SYSTEM FAILURES COULD RESULT IN A FUEL/PROPELLANT SPILL AND SUBSEQUENTLY RESULT IN THE RELEASE OF POTENTALLY EXPLOSIVE OR TOXIC VAPORS INTO THE ATMOSPHERE. THIS PROPOSAL EXPLORES THE FEASIBILITY AND PRELIMINARY DEVELOPMENT OF A MODELING SYSTEM WHICH IS ABLE TO MAKE HIGHLY ACCURATE ASSESSMENTS OF IMPACTS TO GROUND SUPPORT PERSONNEL, EQUIPMENT, AND AIRCRAFT RELATIVE TO SPILLS OF FUELS/PROPELLANTS AND OTHER EVENTS THAT COULD RELEASE TOXIC OR EXPLOSIVE VAPORS. THE PROPOSED PROGRAM WILL MODIFY A SERIES OF EXISTING SOURCE CHARACTERIZATION AND VAPOR DISPERSION MODELS, DEVELOPED FOR THE PETROCHEMICAL INDUSTRY, FOR APPLICATION TO PROBLEMS FACED BY THE U.S. AIR FORCE. THE PHASE I EFFORT WILL DEFINE AND PROVIDE MODELS THAT CAN PROPERLY ASSESS IMPACTS RELATIVE TO TYPICAL SPILL/VAPOR MIGRATION SCENARIOS. PHASE II WILL EXPAND THE MODEL SCOPE WHEREBY PROVIDING A COMPREHENSIVE USER FRIENDLY SYSTEM TO ASSESS IMPACTS RELATIVE TO ALL TYPES OF SPILLS. THE PROPOSED MODELING SYSTEM WILL HELP THE AIR FORCE ALIGN REALISTIC GROUND SAFETY CRITERIA WHICH WILL SAVE OPERATIONAL COSTS AND ENABLE AN INCREASE IN COMBAT SORTIE GENERATION RATE.